This invention relates generally to a feeder for an animal cage, and more particularly to a multiple dosage feeder which selectively exposes one of a plurality of precise dosages of food or other substances to an animal within the cage while covering the remaining dosages.
Animals used in laboratory experiments and housed in cages must be supplied with a nutritionally adequate amount of food to allow for normal growth and development, as well as to permit such animals to ingest various substances in the food for experimental purposes. While it is often not difficult to encourage an animal to eat, many animals which are commonly used in laboratory experiments, such as rats and mice, have a tendency to overeat. In fact, these animals may gorge themselves on any food presented to them and will continue to eat until they become obese and develop obesity-related diseases, often resulting in premature death and thus ruining the experiment. Accordingly, it is important to administer only a measured dosage of food to such animals to prevent such harm. Additionally, in certain experiments, such as those conducted in toxicology labs, it is very important to control and keep track of the exact quantity of food ingested by the animal. Therefore, even where such animals do not die, it is often important to administer only a measured dosage of food at predetermined intervals to control the results of the experiment, and it must be assured that the animal in the experiment does not eat too much food at any given interval.
Traditionally, the administration of measured dosages of food to laboratory animals in cages has been accomplished manually. Typically, laboratory personnel must: (1) measure a single dosage of food into a container; (2) open the cage; (3) remove the empty single-dosage container from the cage; (4) place the filled single-dosage container within the cage; and (5) close the cage. This procedure must be performed once for each cage in the experiment at every feeding interval.
The manual method of administering measured dosages of food suffers from several drawbacks. First, the sheer number of steps involved for each feeding operation makes the process slow and cumbersome. Second, the repetitive nature of the operations increases the likelihood of personnel developing ergonomic injuries. Third, the necessity of opening the cage to remove the empty food container and to insert the filled food container increases the likelihood that the animal within the cage will escape, increases the exposure and hazardous proximity of laboratory personnel to the animal, and inhibits automation of the feeding process. Fourth, since laboratory animals may eat food rapidly, it is possible for laboratory personnel to accidentally feed some animals twice because there is no separate indication as to whether a particular animal has received the current dosage of food.
Accordingly, it is desired to provide a multiple dosage feeder for an animal cage which selectively provides one of a plurality of dosages of food to an animal within a cage in a structure which limits the animal to eating a single dosage at a feeding interval, reduces the number of steps and the time required to administer measured dosages of food to each cage, indicates whether a particular dosage has been administered, and eliminates the necessity of opening the cage to administer the measured dosages of food.